JPS6183230A - Crystalline polyether imide and polyamide acid precursor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyetherimides, more particularly crystalline polyetherimides, and their precursor polyamic acids.

Polyetherimides are a group of known polymers characterized by advantageous properties such as thermal stability and solvent resistance. Examples of these include aromatic diamines such as m-phenylenediamine, and 2-bis[￥-(3,
There is a polymer made by reaction with an aromatic ether dianhydride, which is \-dicarboxyphenoxy)phenyl]propani dianhydride ("bisphenol A dianhydride").

Various polyetherimides of this type are used industrially as engineering resins.

It is known that crystalline polymers are generally more resistant to the action of solvents than their closely related amorphous polymers. However, there are several factors that make it difficult to produce crystalline polyetherimide suitable for commercial production and use. The first is that it is extremely difficult to predict the degree of crystallinity from the molecular structure. Second, many known crystalline polyetherimides have extremely high equilibrium melting points. for example,
The equilibrium melting point (Tm) of the crystalline polymer prepared from bisC3,'l-dicarboxyphenyl)ether dianhydride and m-phenylenediamine is 90°C, and the equilibrium melting point (Tm) of the crystalline polymer prepared from bisC3,'l-dicarboxyphenyl)ether dianhydride and m-phenylenediamine is 90 °C, and the same dianhydride and/or coubis(guaminophenoxy)benzene The product Tm + i y - 0c. Similarly, bis[gu(3,cudicarboxyphenoxy)phenyl]
The Tm values of crystalline polyetherimide prepared from sulfide, p-phenylenediamine and benzidine are &62t'C and '1 (ll>3°C, respectively).
Although polyetherimides are extremely thermally stable, this stability is usually not maintained at temperatures above 0.theta..degree. Therefore, even if a polymer is obtained, it is difficult or impossible to process it because the Tm value is greater than this temperature.

The principal object of the present invention is therefore to provide seven chemical groups of crystalline polyetherimides with closely related molecular structures, and their polyamic acid precursors.

Another object is to provide a crystalline polyetherimide having a sufficiently low Tm value to allow convenient processing and molding.

Yet another object is to provide a crystalline polymer that has many of the desirable properties of commercially available polyetherimides.

Some of the other objectives are self-evident and some are discussed below.

In its broadest sense, the present invention has an equilibrium melting point of 0θ°C.
It consists of a polymer selected from the group consisting of lower crystallinity polyetherimides and their polyamic acid precursors.
This polymer essentially consists of structural units of the following formula (1).

Here, A1 and A2 each have the following formula (2).

(II) Here, Q is divalent oxygen or sulfur, and m and n are each 0 or /. In the above formula (2), X is OH and Y is NH, or X and Y together are N. This structural unit contains at least 7 aromatic rings.

As is clear from the formula (■), the polymer of the present invention is a polyetherimide when X and Y are both N, and X7! ]
"-OH and Y is NH, it is a polyamic acid precursor. Polyetherimide-polyamic acid mixed polymers are also included. As shown in parentheses, each 0-
The A' part is para to one of the C=0 groups, and if X and Y together are N, then of course the λ C=0 groups are equivalent.

A1 residue and A2 residue may be the same or different,
Each/, nu-phenylene, ¥, 'l'-biphenylene,
It falls within a relatively small class of related p-linked groups, including bis(4-phenylene) ether and bis(gouphenylene) sulfide groups. It may thus be considered that the polymer can be obtained by reaction of a tetracarboxylic acid or a functional derivative thereof (for example a dianhydride, ester or bisimide) with a diamine.
These compounds include:

Tetracarboxylic acid: /, \-bis(3, cudicarboxyphenoxy)benzene, '1. ¥'-bis(3,cudicarboxyphenoxy)biphenyl, bis[4l-(
3,'l-dicarboxyphenoxy)phenyl]ether, bisC'l-<3. ￥-dicarboxyphenoxy)
phenyl] sulfide.

Diamine: /, Coubis(guaminophenoxy)benzene, 'l,\'-bis(cuaminophenoxy)biphenyl, bis-14-('g-aminophenoxy)-phenyl]ether, bisC'l-(\-amino phenoxy) phenyl] sulfide.

The p-linked tetracarboxylic acids (and functional derivatives thereof) and diamines listed above are known in the art and can be prepared by known methods.

For example, p-chloronitrobenzene and formula HO-A2-
Diamines can be prepared by reducing the nitro group after a nucleophilic aromatic substitution reaction with the disodium salt of the compound of OH. Similarly, Kounitrophthalimide can be reacted with the disodium salt of a compound of formula HO-A'-OH and the resulting bisimide converted to the dianhydride.

The descriptions of similar nucleophilic substitution reactions and conversion of bisimides to dianhydrides as disclosed in US Pat. Nos. 3 and 7 are incorporated herein by reference.

A further feature of the polymers of the invention is that the structural units therein contain at least 7 aromatic rings. As used herein, the term "aromatic ring" refers to a two-membered carbocyclic aromatic ring.

Since the tetracarboxylic acids and diamines listed above each have 3 or 9 such rings, the structural units of the individual polymers of this invention will contain 7 and more rings.

Finally, the equilibrium melting point ('r
The value of m) must be lower than θ0°C. Generally, the value of Tm is in the range of 200 to 370°C.

The concept of crystallinity is explained in [Complete Book of Polymer Science and Technology (En)
cyclopedia of polymer 5ci
ence and Technology) J, No. 7
Volume, No. 4'19~! It is discussed in considerable detail on page 2ef' (79 Otsu-nen). As explained therein, the fact that a polymer is considered crystalline does not mean that the entire polymer is crystallized.

On the contrary, it means that there are crystalline regions of substantial size throughout the polymer.

For purposes of this invention, a polymer is considered crystalline if it has a certain equilibrium melting point.

The equilibrium melting point is defined as the temperature at which the final crystalline material becomes a liquid.

The polyetherimide of the present invention typically has a polyetherimide of about υ~
, 200° C., by solution or melt polymerization.

This polyetherimide is relatively insoluble in most solvents, so it is usually necessary to use hydroxyaromatic solvents such as m-cresol, and sometimes forms azeotropes with water, such as toluene or xylene. It is used in admixture with aromatic hydrocarbons which facilitate the removal of water. The molar ratio of diamine to dianhydride is usually about θ9j:/
to about /θ oni7, and preferably this value is about /:/ to produce a high molecular weight polymer.

In some cases it may be desirable to use end capping agents such as phthalic anhydride to avoid undesirably high melt viscosities. The amount of such end-capping agent, if present, is typically about .theta.2 to .theta. molar ratio of the total anhydride.

The polyetherimide of the present invention may be produced by a step-by-step process consisting of a first step of producing the polyamic acid of the invention and a Ω step of imidizing the polyamic acid. Typically, the first stage is carried out at a temperature in the range of about 2 to 10 g and the solvent used can be a hydroxy aromatic solvent such as those listed above, but diethylene glycol dimethyl ether or dipolar aprotic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide or N-methylpyrrolidone are most common. 3
7! The polyamic acid is converted to polyimide in the near absence of solvent by heating in the °G range.
This λ-step process is particularly advantageous if a film or fiber-reinforced composite of polynytylimide is desired.

Also, US Application No. 3 (B,
t33, the disclosure of which is incorporated herein by reference, by reacting bisimides of amines containing electron-deficient groups with diamines to produce the polyetherimides of the present invention. is also possible. Usually, this electron-deficient group accounts for at least 7 of the free amine components of the equilibrium mixture obtained by the reaction represented by the following formula (1).
0 mole, most usually at least about 3θ mole, preferably at least about 0 mole
It is derived from 2.

(III) OO This amine Z-NH2 has a boiling point of about 300°G at atmospheric pressure.
Lower is preferred, typically lower than 230°G, about 2
More preferably, the temperature is lower than 70°C, /e! ? Most preferably, the temperature is below 0°C. The highest boiling point of about 300°C is absolute. These lower boiling points are slightly more preferred when the amine accounts for less than about 7 TamA% of the free amine component of the equilibrium mixture. A lower boiling point is preferred in order to easily shift the equilibrium towards polyneuimide formation during the reaction with the diamine.

It will be clear to those skilled in the art how to equilibrate the reaction represented by formula (II) and analyze the equilibrium mixture.

In a typical method, a mixture of 0θθomole each of aniline and N-(Z-substituted)phthalimide was purged with nitrogen/Q
ml stainless steel reaction vessel, sealed and heated to 230° C./hr in a constant temperature bath.

The reaction tube is then removed, cooled, opened and a sample of the reaction mixture is taken and analyzed by high pressure liquid-liquid chromatography.

The main chemical property of the Z residue is its high degree of electron deficiency. In many cases, suitable electron-deficient groups consist of aromatic hydrocarbon groups containing seven or more strongly electron-withdrawing substituents and heterocyclic groups having aromatic character.

Suitable aromatic hydrocarbon groups include phenyl, naphthyl, and the like containing substituents such as halo, nitro, keto, carbalkoxy, cyano, and perfluoroalkyl. Preferably, at least seven of the electron-withdrawing substituents are ortho or para to the free valence bond (ie, the one bonded to the amino group of Z-NH2). Particularly preferred is trifluoromethylphenyl.

Suitable heterocyclic groups having aromatic character include those having o- or o-membered rings with aromatic unsaturation of the type found in pyrrole and pyridine.

Preferably, these groups contain 7 to 3, especially 7 or 2, hetetato atoms, of which at least 7 are nitrogen and if the others are nitrogen or sulfur. These are usually unsubstituted, but may be substituted, particularly with electron-withdrawing substituents as exemplified above. It is preferred that the free valence bond is in the 2- or g-position relative to the heteroatom. If the ring contains more than 7 hetetato atoms, especially if it is an o-membered ring, it is preferred if the free valence bond is attached to the only carbon atom between the two hetetato atoms.

! Examples of negative heterocyclic groups include pyrrolyl, di-thiazolyl, -imidazolyl and 2-(/, 3.'l
-thiadiazolyl). Examples of 6-membered ring groups include 2-pyridyl, 3-pyridyl, goupyridyl, 2-pyrimidyl, -1pyrazyl 1,2-(/.

gouthiazolyl) and 2-<7.3-thiazolyl). Particularly preferred Z groups are aminopyridyl groups, especially -1pyridyl and goupyridyl.

Since the polyetherimide of the present invention is crystalline, it has high resistance to the action of solvents. They are generally only soluble in substantial proportions in hydroxyaromatic solvents such as m-cresol and O-chlorophenol, and often only at elevated temperatures. As previously mentioned, these Tm values are typically in the range of about 20[theta] to 370[deg.]C.

The following examples illustrate the preparation of crystalline polyetherimides of the present invention.

Examples /~/3 Dianhydride ζ gram-mol, phthalic anhydride θ/ and gram-mol, diamine 90 gram-mol, m-Freseau J
L, 3. ! ml and t JL Engineering: / , i > ml were prepared from the diamines and dianhydrides listed in Table 1,
The mixture was heated to reflux with stirring under nitrogen. Refluxing was continued while water was removed by distillation. After / hour, a trap filled with &A molecular sieve was inserted into the distillation system, and reflux was continued for an additional hour.

The reaction mixture was diluted with approximately 3θml of m-cresol, cooled, and poured into methanol with stirring.

The precipitated polymer was filtered, washed with methanol and dried under vacuum at 700°C.

All polymers of Examples/-/3 were insoluble in chloroform, toluene, dimethylacetamide and dimethyl sulfoxide. Various temperatures of these polymers (
(all temperatures in degrees Celsius) and solubility parameters are shown in Table ■.
Tm and thermogravimetric analysis (TGA) (in nitrogen and air)
Comparing the values, the processing of the polyetherimide of the present invention "
This will serve as an indicator for the "Counter (adoption/rejection consideration)".

Table I /1,4-phenylene, g'-biphenylene x x, g'-biphenylene 1
,4-phenylene,j //
Gu, Gu'-biphenylene 2 〃
Gu, Gu'-biphenylene/2
〃G,G'-biphenylene table ■ TGA /23θ 3 Og E20 G20 . 2,! 10. 297
K otsu 0 j3 e 3 . 20/ 333 g90 g90 g 62. ! , 2 3 tough 5 otsu j evening 3
(Evening recognition 203 Otsu / 330 jet Otsu 20 and
Ω9θ jgu0 guotsu0 7.20otsu 33gu! 20! 62t and flood θ33
/ Otsu tago, f3r 9 2// 33gu j/ogu and (10/9gu,
, 29g 3.20 3θo // 620/ ,,
2.111>θ g20 g20/62. 20!
3.23 Gua 0 Doug 0/3/i Otsu 32 and
j/o 100 S=soluble, SS-somewhat soluble,! = insoluble soluble IS
SI S
11
1 5Sss
s
sl 1
1ss
s sl
1
11 S
S The crystalline polyetherimide of the present invention can be used to form films, molding materials, fiber reinforced composites, coatings, etc. Their use is particularly advantageous in applications where high solvent resistance is desired.

Typical areas of use are the automotive and aircraft industries, for structural, decorative and protective purposes, as high temperature electrical insulation and dielectrics for capacitors, as coil and cable jacketing, for vessels and vessel linings, and for various applications. It is used in laminated structures applied as films for heat-resistant or other types of materials, as well as in filled compositions with fillers such as asbestos, mica, glass fibers, etc.

Other uses include as a binder for asbestos fibers, carbon fibers and other fibrous materials in the manufacture of brake linings, and as a binder for asbestos, fiberglass, talc, quartz,
There are applications for formulating molding compositions using fillers such as wood flour, finely divided carbon and silica. Other uses are similar to those described in US Pat. Nos. 39 and 3093, the disclosures of which are incorporated herein by reference.

Claims (1)

Claims: (1) A polymer selected from the group consisting of crystalline polyetherimides and their polyamic acid precursors having an equilibrium melting point of less than 400°C, the polymer essentially having the formula I: ( I ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, A^1 and A^2 are each formula II: (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, Q is a divalent (oxygen or sulfur, m and n are each 0 or 1), X is OH and Y is NH, or X and Y taken together are N]. , said polymer in which said structural unit contains at least 7 aromatic rings. (2) The polymer according to claim 1, which is a polyetherimide in which X and Y together form N. (3) The polymer according to claim 2, which has an equilibrium melting point in the range of 200 to 370°C. (4) The polymer according to claim 3, wherein A^1 is a 1,4-phenylene group. (5) The polymer according to claim 4, wherein A^2 is a 4,4'-biphenylene group. (6) The polymer according to claim 4, wherein A^2 is a bis(4-phenylene) ether group. (7) The polymer according to claim 4, wherein A^2 is a bis(4-phenylene) sulfide group. (8) The polymer according to claim 3, wherein A^1 is a 4,4'-biphenylene group. (9) The polymer according to claim 8, wherein A^2 is a 1,4-phenylene group. (10) The polymer (1) according to claim 8, wherein A^2 is a 4,4'-biphenylene group.
1) The polymer according to claim 8, wherein A^2 is a bis(4-phenylene) ether group. (12) The polymer according to claim 8, wherein A^2 is a bis(4-phenylene) sulfide group. (13) The polymer according to claim 3, wherein A^1 is a bis(4-phenylene) ether group. (14) The polymer according to claim 13, wherein A^2 is a 1,4-phenylene group. (15) The polymer according to claim 13, wherein A^2 is a 4,4'-biphenylene group. (16) The polymer according to claim 13, wherein A^2 is a bis(4-phenylene) sulfide group. (17) The polymer according to claim 3, wherein A^1 is a bis(4-phenylene) sulfide group. (18) The polymer (19) according to claim 17, wherein A^2 is a 1,4-phenylene group.
18.) The polymer according to claim 17, wherein A^2 is a 4,4'-biphenylene group. (20) The polymer according to claim 17, wherein A^2 is a bis(4-phenylene) sulfide group.